What is Beam: Definition and 1000 Discussions

An I-beam, also known as H-beam (for universal column, UC), w-beam (for "wide flange"), universal beam (UB), rolled steel joist (RSJ), or double-T (especially in Polish, Bulgarian, Spanish, Italian and German), is a beam with an I or H-shaped cross-section. The horizontal elements of the I are flanges, and the vertical element is the "web". I-beams are usually made of structural steel and are used in construction and civil engineering.
The web resists shear forces, while the flanges resist most of the bending moment experienced by the beam. The Euler–Bernoulli beam equation shows that the I-shaped section is a very efficient form for carrying both bending and shear loads in the plane of the web. On the other hand, the cross-section has a reduced capacity in the transverse direction, and is also inefficient in carrying torsion, for which hollow structural sections are often preferred.

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  1. P

    Calculate the maximum vertical point force P that this beam can sustain

    A simply-supported steel beam with a vertical point force P is shown in Fig. 2(a). A cross-section of the beam, which is composed of two identical C-shaped members bolted back-to-back, is shown in Fig. 2(b). Both C-shaped members have a uniform thickness of 1 cm. Pairs of bolts are located at a...
  2. J

    Static equilibrium: mass on beam

    A diagram of the physical situation is below: Choosing the positive ##y## direction to be upwards and the positive direction of rotation to be counterclockwise, Newton's linear second law gives: $$-m_D g + F_L + F_R = 0$$ where ##F_L## is the magnitude of the force exerted on the bar by the...
  3. M

    Deflection of a cantilever beam with applied tension at the free end

    Not much to add since the question is fairly simple, but again I'm wondering if applying tension at the free end of a cantilever beam affects the deflection it would have if only itself weight is considered. Intuitively, tension should tend to straighten the beam, and if it does, how to...
  4. K

    Cantilever beam deflection with point mass and point load at the end

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  5. C

    Size of a light beam before and after Refraction

    The size of light beam is same or different before and after refraction from a medium. If same then why we can not prove from mathematical expression. If not same why?
  6. Erik Ayer

    I Interference of a fat laser beam: Tilting wave peaks

    I want to split a fat laser beam and interfere it with itself, kind of like this: The very obvious problem is that the wave peaks shown as black lines would be a whole lot closer together, so the interference fringes would be sub-microscopic. If a couple of glass wedges - oddly-shaped prisms...
  7. A

    I Transmission electron microscope beam focusing

    So I'm reading up on this device and what I get is that in all electron guns once the electrons are emitted they would tend to repel one another so in order to make the beam focused instead of spread out across, one uses magnetic fields in the electron microscope, So after the focused beam hits...
  8. S

    Polarization and intensity of a Gaussian beam

    The equation above (from Wikipedia), assumed that the Gaussain beam has polarization in x-direction, as I know that the polarization means that the oscillation direction of the electric field and so the intenisty... so how we get circular intensity in every direction which means in x and y...
  9. S

    Why is the edge of the light from my flashlight beam so blurry?

    On the photo you can see: Red 1: the edge is very sharp (as expected) Red 2: the edge is very blurry (but why?) Same for green. You can also see (Red 2) that the blurry edge is yellow. What is this effect called?
  10. J

    MHB Light Beam Speed on Shoreline from P - 16km

    A lighthouse is located on a small island 16 km off-shore from the nearest point P on a straight shoreline. Its light makes 5 revolutions per minute. How fast is the light beam moving along the shoreline when it is shining on a point 3 km along the shoreline from P?
  11. P

    Can I Transform Multiple Steel Beams into a Single Piece of Concrete?

    When I convert the steel beams to concrete, do I transform the several different beams into a single piece of concrete in order to do the calculations to find the second moment of area of the beam or do I transform each beam seperately into a concrete piece? Intuitively, t seems reasonable to...
  12. S

    I Calculating force when landing on a beam

    I am designing a machine at the moment, and I am struggling to get my head around impact forces. I have established that the force applied is mgh/d, but I am struggling to work out the value for d. Taking it in isolation, assuming that the falling weight does not "give" in any significant way...
  13. B

    Deflection distance for an electron beam in an electric field

    Have tried doing this question but I'm a bit confused on where I'm going wrong This is what I have done but get a value that doesn't match to any of the options given above? Any help would be really appreciated, Thanks!
  14. C

    Engineering Where does the bending moment exerted by a wall on a beam come from?

    M = r x F r = 0 ∴ M = 0 But this is clearly wrong. For some reason, the "reaction moment" must exist. Why? Where does it come from? More specifically, which force(s) produces the bending moment, and at what distance(s)? Does it come from the reaction force form the wall on the left end of the...
  15. BeyondBelief96

    I Use of the Beam Splitter Operator

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  16. BeyondBelief96

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  17. BeyondBelief96

    A Two Different Fock State Inputs into a Beam Splitter

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  18. E

    Radiation shielded Go-Pro camera sent through electron beam irradiator

    A radiation-shielded go-pro camera was sent through an electron beam irradiator. You can see the effects that the radiation has on the camera in the video. I wonder how many rads it was exposed to.
  19. cs44167

    Torque on a Beam Due to Gravity

    I tried using r * f * sin theta and calculated this: 1.14 m * 9.80 m/s/s * 7.78 kg = 109.7 N*m this was wrong; I needed three significant figures so I did 1.10E2 N*m which was also wrong. Since the torque is due to gravity; would it be -1.10E2 N*m since it’s angle is -270° which is -1?
  20. T

    Quick Method of Calculating the 2nd Moment Of Area Of an I Beam

    Hi All I was wondering if there was a quick method of calculating the Second Moment Of Area about the Z axis shown below? I can quickly work out the Second Moment Of Area about the Y axis but the Z axis is proving very difficult and time consuming as the parallel axis therom needs to be...
  21. T

    Calculating the bending stress of a simply supported beam

    Hello all I am trying to calculate the bending stress of a simply supported beam with a load of 12kn at the middle of a 6m span, member depth of 0.016m I have drawn both the bending moment and shear force diagram. I want to know the following:- 1) When calculating the bending stress would...
  22. T

    Crane Arm Model using beam theory

    Can a Bernoulli or Timoshenko model be reasonable for a crane arm, on ships? Yes, the arm might have a truss element, yes there is a hydraulic force to lift the arm (or cables). But to some extent, can one model the crane arm as one of a simple beam (either Timoshenko or Bernoulli -- and...
  23. Srinath

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  24. DEvens

    I Wave function of a laser beam?

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  25. L

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  26. Z

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  27. M

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  28. benny1993

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  29. Zouatine

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  30. A

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  31. robot6

    Two Beam Problem: Solve 6 Equations, 7 Unknowns

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  32. N

    Optimal beam geometry for 3-point bending

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  33. D

    Engineering Torsion and deflection of a rectangular beam

    Hello I would like some feedback about a problem. The idea is to calculate how much the angled bit of this beam moves things to account for are deflection and torsion. Did i miss anything? Underlined with red are the displacements in millimeters. In the picture the dotted line is the axis that...
  34. fpjeepy

    Simplified Tapered Cantilever Beam Generalizations

    I looked in Roark's Formulas and didn't find anything. Basically, I design parts that need to bend. Mostly plywood and plastic. Mostly cantilever beams. I like to taper the beams so that the stress along the beam is more uniform. The question I have is how much do I taper. With no taper, the...
  35. F

    Solving Shear Force and Bending Moment at Reaction Point R

    Hello Please see attached - trying to figure shear force and bending moment at reaction point R, with a horizontal force applied at top of Z. This is a veranda deck with balustrade. If F was vertical, then straightforward with SF = F and M = FX. But when F is horizontal as shown, I'm having...
  36. jchan79

    Find Torques frm Gravity & Buoyancy on Beam Cross-Sections

    The hint says that "The cross-section of the underwater part of the beam could be represented as a superposition of a rectangle and two symmetrically positioned narrow triangles (one of them of negative mass)." How do I find the torques from gravity and buoyancy on these figures?
  37. S

    Resultant moment of beam fixed at one end

    Hi all, I just wanted to get some clarification on 'resultant moment' when calculated in 2D for a beam which is fixed at one end (point A), and has a load applied at the opposite end (point B). My interpretation of 'resultant moment' would be calculated as sum(M) = Ma + FL, where Ma is the...
  38. A

    Bubble chamber experiment on a K− beam

    Hello everybody! Let's begin with the spin. Spin of the ##\Lambda## is ##1/2## and of the pion is ##0##: $$ \frac{1}{2} \otimes 0 = \frac{1}{2}$$ Since I know from the homework statement that ##L=1##: $$ \textbf{J} = \textbf{spin} \otimes \textbf{L} = \frac{1}{2} \otimes 1 = \frac{1}{2} \oplus...
  39. lLehner95

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    In the center of mass frame of reference i found that ##p^{*}=\frac{[(M^{2}-m_{\nu}^{2}-m_{K}^{2})^{2}-4m_{\nu}^{2}m_{K}^{2})]^{1/2}}{2M}##. I don't know how to find the momentum distribution ##p_{L}(\theta)## considering that i have 2 different mesons with a specific number ratio...
  40. Q

    Converting source intensity to the maximum reach of beam flux

    We can solve for the maximum 5 lux illumination distance with the above equation. E = 10.76*(35,000/d^2) d = 275 feet (approximately). However, the 5 lux illumination distance is not 275 feet. The 35,000 cd value is not an axial intensity value. It is at a point that is slightly down and to...
  41. G

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  42. L

    Is a particle beam or laser beam conductive?

    If particle beam or laser beam weapon would be used to cut the electrical wires in high voltage transmission lines of the enemy. Could the current conducts into the particle beam (or laser beam) itself and can short circuit in the weapon platform? I know ionized air can conduct electricity...
  43. M

    What can be used to change the direction of the laser beam?

    Let's say we have a laser beam coming from a source called X, we would like to change its direction so that it would hit directly on the object that we have. What would be the possible solutions?
  44. R

    Deflection of Fixed Rotated Beam

    W14 x 30: d = 13.84" = 0.352 m w = 6.730" = 0.171 m tw = 0.270 = 0.00686 m tf = 0.385 = 0.00978 m 40' = 12.192 m 18" = 0.4572 m ρ = 997 kg/m3 E = 1.4*109 Calculate Weight of water: V = A*L = π*(0.4572)2/4 *12.192 = 2.0016m3 W = m*g = ρ*V*g = 997*2.0016*9.81 = 19.576kN uniformally distributed...
  45. B

    I Focused proton beam waist diameter

    According to this link (https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/collisions.htm) the LHC achieves a beam waist diameter of approximately 64 microns. What limits them from getting a tighter focal point? Are lower energy beams easier or harder to focus tightly?
  46. jason3w

    Create a focused beam angle of LED light using reflection

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  47. S

    Fixed-End Beam with Center Static Load

    The bracket shown in figure 1 is applied to both ends of a beam (figure 2) which experiences a single static load at its center. The bottom of both brackets are fixed by some method, so it can't deflect. According to Solidworks, the bracket survives with flying colors, but it bothers me that I...
  48. Teslosifone

    Irregular free-free beam, non-numerical solutions

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  49. D

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  50. B

    Parallel Plate Pulsed Proton Beam Generator (Thought Experiment)

    I am trying to come up with a design for a device with which to generate a rapidly pulsed proton beam (on the order of 1 pulse per ms). My thought was to apply a 10 kV potential between two parallel plates (each with a hole in their center) and inject a steady stream of hydrogen gas through the...
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